Production And Evaluation Of A New Micro Cross Channel Capable Of Providing Stable Biochemical Gradients

Cell migration and chemotaxis play an important role in many physiological and pathological processes,such as embryonic development, tissue repair and tumorigenesis. In the micro-environment,a variety of physical and chemical factors cause cell migration,chemotaxis.In rencent years,more and more people are concerned about the cellular microenvironment and the interaction of cells in the field of cell biology.Some soluble factor interactions of cellular and it's extracellular micro environment can control cell proliferation, movement and differentiation.The distribution of these soluble factors in extracellular matrix is not uniform in the same, the concentration gradient and distribution of biological molecules change with time and space.To simulate the micro environment of cells in the body better,the first key step is understanding the mechanism of physiological and pathological conditions.Traditional models, such as the transwell chamber, boyden chamber,agarose plates and other small rooms, can only provide a static,two-dimensional environment for cell growth,and can not produce space-time adjustable, more precise biochemical gradients.Furthermore,the in vitro environment is still different from in vivo. So many in vitro studies are often not consistent with the in vivo situation.In the past two decades, microfluidic technology based on polydimethylsiloxane developed rapidly.It not only produces stable and controllable gradient of soluble factors,but also maintains long time and stable gradient and unchanged.But the micro-chip is produced using lithography, it is disadvantaged by process complexity, costly, production cycle is long and not easy to experiment in a timely manner, etc.This paper based on the Biorheology Science and Technology Laboratory's study of production of microfluidic chip.This paper proposed a new method of microfluidic chip production.Microfilaments are embedded in PDMS.When solidified,removing it from PDMS.Thus the process of chip production is completed.This new chip is suitable for cell culture and carrying out experiments in micro-channels.The micro channel with height of 500μm,can generate more than 120 hours of continuous concentration gradient and pressure gradient.The concentration gradient and pressure gradient are qualitative analyzed using the software COMSOL Multiphysics 3.5a.Finally, the channel is used in vascular endothelial cells (VECs) chemotaxis, migration experiment,observing the VECs chemotaxis induced by vascular endothelial growth factor (VEGF) concentration gradient.Compared with no gradient group,after 6 hours induction, cells evenly distributed in the center of the channel migrated toward the direction of higher concentration gradient.The PDMS microfluidic chip using mold spinning method can generate a stable concentration gradient and pressure gradient.In this chip, a stable chemical and biological gradient can be generated and inducing cells chemotaxis and migration.Since this new method is cheap, simple and effective, it can continue to be developed as pre-experimental device for three-dimensional cell culture,chemotaxis and migration.